Splice between two ends of yarn

ABSTRACT

The invention relates to a splice between two ends of yarn, the ends of yarn, positioned to point at each other without increase in diameter, each being joined over a length of yarn to at least one longitudinal strip. The longitudinal strip is provided on its side facing the ends of yarn with a joining agent, said joining agent permanently binding the ends of yarn over the respective length of yarn to the longitudinal strip in frictional non-positive manner.

BACKGROUND OF THE INVENTION

The invention relates to a splice between two ends of yarn as required,for example, when, in the continuous processing of a yarn which is beingunwound from one yarn spool, the end of the yarn is reached and itbecomes necessary for the starting part of the yarn supplied fromanother yarn spool to be spliced to the end. Such an operation takesplace, in particular, when there is a change of warp beams in weavingmachines, when the yarn wound onto one warp beam reaches its end and itbecomes necessary for the starting part of the corresponding yarn from anew warp beam to be spliced to the aforementioned end, there resulting amultiplicity of such splices across the width of the warp beam.

The conventional method, employed in connection with the above-describedapplications, of splicing the end of one yarn to the starting part ofanother yarn consists in the operation of tying, as described, forexample, in DE OS 17 10 938. According to this publication, the startingpart and end are held by clamping and are then subjected to a tyingoperation which is performed by a complicated mechanism. A further knownmethod of splicing consists, according to DE OS 32 47 162, in coaxiallyaligning the yarns with respect to each other with a small distancebetween them and in holding them in this position using clampingdevices, whereupon a bonding agent is introduced in dosed droplet forminto the gap between starting part and end of the yarn, with rollersacting on the place of bonding and rotating said place of bonding inorder, at the place of bonding, to obtain a diameter equal to thediameter of the overall yarn.

The method of mechanically tying together the starting part and end ofthe yarns results in a considerable degree of mechanical complexity withcorresponding intensity of maintenance. Furthermore, there is aconsiderable increase in the diameter of the yarn at the place of tying,this making it impossible in many applications for the yarn to becontinuously processed, because, in a weaving machine, for example, theyarn has to run through harnesses and the weaving comb. When the weavingcomb is operated, it is moved very closely past the yarn at high speed,wherein a place of tying is exposed to quite considerable frictional andtensile stresses, which may result in the yarn tearing at the place oftying. The continuous processing of tied yarns on weaving machines is,therefore, impossible at present. For this reason, when use is made ofthe presently conventional method of mechanical tying, an attempt ismade to employ the maximum possible lengths of yarns on the warp beamsin order in this manner to save on the effort of individually tying allthe yarns on the warp beam, something which is associated with aconsiderable expenditure of time. The consequence of this is that smalllot sizes, which would be economically advantageous for relatively shortlengths of woven goods, are virtually never produced, because this wouldnecessitate correspondingly shorter lengths of yarn on the warp beams.The additionally known method of introducing a droplet of bonding agentinto the gap between the starting part and end of a clamped yarn isvirtually never used because, particularly in the case of thin yarns,there is a correspondingly small bonding zone which is not capable ofwithstanding a high tensile stress during the processing of the yarn andwhich, therefore, has a tendency to tear.

Known from EP 0 989 218 A1 is a further method of splicing an end ofyarn to a starting part of yarn according to which the end and thestarting part are firmly held in a position in which they overlap over aconsiderable length and are twisted together in that position. In orderto provide this twisted region with the necessary tensile strength andresistance to reverse twisting, a bonding agent is dabbed onto thetwisted region. This method, therefore, comprises two successive processsteps, it being necessary first of all for the intertwisted yarns to befirmly held in said position until the bonding agent, having been dabbedonto the twisted region, has set. This slows down the process soconsiderably that it has not been able to establish itself in practice.It must also be taken into consideration in this connection that thetwisted yarns have the tendency to twist back, as a consequence of whichthe splice is from the outset given the tendency automatically to becomeundone unless the bonding agent joins the two yarns together reallyfirmly.

BRIEF SUMMARY OF THE INVENTION

The object of the invention is to create a splice between two ends ofyarn, said splice being capable of withstanding considerable frictionaland tensile stresses and additionally leading to only insignificantthickening at the place of the splice. The object of the invention isachieved in that the ends of yarn, positioned to point at each otherwithout increase in diameter, are each joined over a length of yarn toat least one longitudinal strip, said longitudinal strip being providedon its side facing the yarns with a joining agent, said joining agentpermanently binding the ends of yarn over the respective length of yarnto the longitudinal strip in frictional non-positive manner.

With this design of splice, the forces acting on the splice during theprocessing of the yarn are extended over a length of yarn which may beof corresponding length depending on the type and loading of the yarn,so that the splice is able permanently to withstand the forcesoccurring, in particular, during the further processing of the yarn. Thelength in question, therefore, may be, for example, of the order ofmagnitude of a few millimeters or more. Thus, with a resistantlongitudinal strip adapted to the occurring forces, it is possible toensure that the thus spliced yarn can be exposed to high tensile andfrictional forces without the latter destroying or causing thelongitudinal strip to tear. The longitudinal strip results in only asmall increase in diameter at the place of the splice in comparison withthe diameter of the yarn, because the two ends of yarn themselves arefirmly held in a position pointing at each other in which there is noincrease in diameter, i.e. especially in abutting manner withsubstantially transversely extending cut-off sections or with bevels atthe end and at the start of the ends of yarn, which are able to overlapover the bevelled section without there being an overall increase indiameter. The thus produced splice is also characterized in that itcontains no self-undoing forces.

The material of the longitudinal strip may be, in particular, knownplastics, such as PVC or polyester, which, even when in the form ofparticularly thin longitudinal strips, are capable of withstanding hightensile and shearing forces, and this with a thickness of, for example,0.05 mm.

The frictional non-positive connection between longitudinal strip andend of yarn is advantageously produced in that a bonding agent is usedas the joining agent. Another likewise suitable joining agent is athermoplastic. The aforementioned joining agents are ones which areapplied to the respective longitudinal strip. In addition, it is alsopossible to make the longitudinal strip itself the joining agent in thata thermoplastic is used for the material of the longitudinal strip. Inaddition, it is possible for the joining agent to be in the form of ahook-and-pile fastener, wherein the surface of the longitudinal stripfacing the yarn and the surface of the end of the yarn form those partstypical of a hook-and-pile fastener, namely the hook side and the pileside.

The splice between end of yarn and longitudinal strip may advantageouslybe of such design that the longitudinal strip encompasses the respectiveends of the yarn. This results in a splice between longitudinal stripand end of yarn over a wide region of the circumference of the yarn andconsequently in a particularly resistant splice. However, it is alsopossible to join the ends of yarn together using two opposinglongitudinal strips, as a result of which the forces acting on thesplice are transmitted to two longitudinal strips. In order to make thesplice particularly intensive, the longitudinal strips are disposed insuch a manner that they project away from the ends of yarn radially tothe sides and are joined together in said region.

A further possibility for strengthening the splice consists in that theends of yarn are held at a distance from each other and each end of yarnis held between two longitudinal strips, said longitudinal strips beingjoined together in the region between the ends of yarn. An especiallystrong splice is achieved in that the longitudinal strips themselves arejoined together in the region between the ends of yarn.

If two longitudinal strips are used for attachment to each end of yarn,they can advantageously be overlappingly joined together at the sides,this resulting in an especially high degree of loadability in the regionof the overlap, which overlap may be of sufficient length. Of course,possible for the longitudinal strips to be abuttingly joined together.With such a joint, however, it is necessary to use a joining agent ofparticular tensile strength at the joint, because the entire tensileload and therefore the stresses occurring in the splice are concentratedat that point.

A further possibility for producing the splice consists in joiningtogether the two pairs of longitudinal strips by means of at least onefurther longitudinal strip. In this case, the aforementioned joint iscovered by a further longitudinal strip covering the joint, thiscorrespondingly strengthening the splice.

As described above with respect to its various embodiments, the spliceis required in many different arrangements for the processing of a groupof warp threads sup-plied, for example, to a weaving machine andtransversely across such a group of warp threads. In this case, thesplices may be juxtaposed. It is, however, also possible for the splicesto be provided in staggered manner one behind the other, this being ofadvantage if particular importance is attached to the transversedimensions of the group of warp threads in the region of the splices. Insuch a case, the staggered arrangement is of advantage.

DESCRIPTION OF THE DRAWINGS

Example embodiments of the invention are presented in the drawings, inwhich:

FIG. 1 shows a splice between two ends of yarn with one singlelongitudinal strip;

FIG. 2 shows a section through the arrangement according to FIG. 1 alongthe line II—II;

FIG. 3 shows a splice with a longitudinal strip partially encompassingone end of yarn, in section;

FIG. 4 shows a further variant with a longitudinal strip encompassingmost of the end of yarn, in section;

FIG. 5 shows a splice with two opposing longitudinal strips, in section;

FIG. 6 shows a splice with two opposing longitudinal strips, each almosthalf-encompassing the end of yarn, in section;

FIG. 7 shows a splice with two longitudinal strips, said longitudinalstrips projecting laterally from the end of yarn and being joinedtogether there;

FIG. 8 shows a representation similar to that in FIG. 1, the underlyingdesign being that according to FIG. 7 and the ends of yarn being cut offsubstantially transversely;

FIG. 9 shows a splice similar to that in FIG. 8, but with the ends ofyarn cut off at an oblique angle;

FIG. 10 shows a splice with overlapping longitudinal strips, saidlongitudinal strips being joined together by a frictional non-positiveconnection;

FIG. 11 shows a splice with two longitudinal strips for each end ofyarn, the longitudinal strips of each end of yarn meeting each other inabutting manner;

FIG. 12 shows a splice similar to that in FIG. 11, but with a furtherlongitudinal strip making the spliced connection;

FIG. 13 shows a splice similar to that in FIG. 12, but with twoadditional longitudinal strips making the spliced connection;

FIG. 14 shows a top view of a group of yarns with juxtaposed splices;

FIG. 15 shows a group of yarns with staggered splices disposed onebehind the other, arranged in two rows of splices;

FIG. 16 shows an arrangement similar to that in FIG. 15, but with fourrows of staggered splices disposed one behind the other;

FIG. 17 shows a basic representation of a device for making the splicesfor a group of yarns.

DETAILED DESCRIPTION

FIG. 1 shows a splice between two ends of yarn 1 and 2 positioned topoint at each other. On their sides facing each other, the two ends ofyarn 1 and 2 have substantially radial interfaces 3. The connectionbetween the two ends of yarn 1 and 2 is established by the longitudinalstrip 4, which is permanently joined to the two ends of yarn 1 and 2 bya frictional, non-positive connection by means of a bonding agentcarried by the longitudinal strip 4. The longitudinal strip 4 is of aplastic material, a known thermoplastic being used as the bonding agent.Consequently, the longitudinal strips 4 effectively results in onecontinuous yarn which includes the two ends of yarn 1 and 2 and whichhas only a small increase in cross section in the region of thelongitudinal strip 4, with the result that a thus spliced yarn canreadily be further processed.

FIG. 2 shows a section along the line II—II in FIG. 1.

FIG. 3 shows a sectional representation of a modified version of asplice according to FIGS. 1 and 2. The splice in FIG. 3 comprises alongitudinal strip 5 which encompasses the end of yarn 2 virtually overan area of around 180° and which therefore provides a splice withparticular load-bearing capacity.

FIG. 4 shows a splice in which a longitudinal strip virtuallyencompasses the entirety of the end of yarn 2. As can be seen, thelongitudinal strip 6 in this case extends so far in the circumferentialdirection of the end of yarn 2 that only a narrow gap is left betweenthe edges of the longitudinal strip 6.

FIG. 5 shows a splice in which two longitudinal strips 7 and 8 are used.The two longitudinal strips 7 and 8 are joined to the end of yarn 2 (andto the other end of yarn, not shown) by means of the two longitudinalstrips 7 and 8, the two longitudinal strips each extending over only arelatively small part of the circumference of the end of yarn 2.

According to FIG. 6, there are two longitudinal strips 9 and 10, whicheach encompass the end of yarn 2 almost to the same extent as shown withregard to a longitudinal strip in FIG. 3.

FIG. 7 shows a splice which likewise comprises two longitudinal strips11 and 12, which, however, project radially at the sides and thus formtwo wings 13, 14 in the region of which the longitudinal strips 11 and12 are joined together. The splice in FIGS. 13 and 14 can in this casebe made particularly intensive, with the result that this type of spliceis particularly resistant to friction and tensile stresses.

The representation in FIG. 8 is a side view of a splice according toFIG. 7, the latter being a sectional representation. It can clearly beseen from FIG. 8 how the facing sides of the ends of yarn 1 and 2 areformed, namely similarly to the embodiment shown in FIG. 1, by asubstantially radial cut 3, which then exists, of course, on both endsof yarn 1 and 2.

With regard to the actual splice, FIG. 9 shows the same embodiment as inFIG. 8, but, in this case, there is a different design of the innersides of the two ends of yarn 1 and 2, which, in this case, mutuallyoverlap through being cut at an oblique angle.

The above-described embodiments are ones in which the longitudinalstrip(s) which make the splice extend over the two ends of yarn 1 and 2,with the result that any occurring tensile forces are transmitted fromone end of yarn, e.g. 1, to the respective longitudinal strip 11 or 12and from there to the other end of yarn 2. However, it is also possiblefor the splice to be made in a different manner, namely in that thelongitudinal strips are provided between the facing sides of the ends ofyarn 1 and 2 with an overlapping or abutting joint, which then absorbsthe occurring tensile forces.

For this purpose, FIG. 10 shows an embodiment in which the two ends ofyarn 1 and 2 are each joined by two longitudinal strips 15/16 and 17/18,the longitudinal strips 15/16 projecting into a space between the twoends of yarn 1 and 2 and overlapping in this region with thelongitudinal strips 17 and 18. In the region of the overlap, thelongitudinal strips 15/16 and 17/18 are firmly joined together, forexample, by means of a bonding agent, this, therefore, establishing thesplice between the two ends of yarn 1 and 2.

A variation on the splice shown in FIG. 10 is presented in FIG. 11, inwhich the longitudinal strips 15/16 and 17/18 meet in abutting manner atthe joint 19; which at the same time forms a bonded joint or weldedjoint. Given sufficient bonding power of the bonded joint or weldedjoint, this design is sufficiently resistant to tensile forces andfriction.

A further variation on the design shown in FIGS. 10 and 11 is presentedin FIG. 12, in which the longitudinal strips 15/16 and 17/18 maintain asmall distance from each other, said distance in this case being bridgedby a further longitudinal strip 20. Said longitudinal strip 20 is gluedon at the facing ends of the longitudinal strips 15/16 and 17/18 andthus forms the splice between the two ends of yarn 1 and 2.

A reinforced splice is shown in FIG. 13, in which, instead of just onelongitudinal strip (the longitudinal strip 20 according to FIG. 12), afurther longitudinal strip is provided, there namely being the twolongitudinal strips 21 and 22, which are opposite each other and whichhold together the ends of the pairs of longitudinal strips 15/16 and17/18 by means of a bonded connection.

The making of splices between two ends of yarn is of particularimportance in connection with the manufacture of textiles, especially inconnection with the weaving of textiles, wherein groups of yarns aresupplied to the corresponding processing machine. Using the presentlyconventional technique, this is done by removing the groups of yarnsfrom warp beams onto which the individual yarns are wound side by side.In order not to interrupt the operation of the processing machine for anunnecessarily long period of time, as the warp beams come to the end theaffected ends of yarn must be joined to the ends of yarn of a new warpbeam, for which purpose it is necessary to join together a large numberof yarns, namely up to several thousand yarns. This method of splicingis, therefore, a technique which represents an essential and technicallycomplex step in the production of textiles. Owing to the considerabletime required for making the splices, efforts are made to use warp beamswhich are as large as possible, which, however, makes it compulsory toproduce correspondingly large lot sizes within which there is thencorrespondingly seldom the need to make a large number of splices. Inthe case of the production of standard goods, the large lot sizesgenerally represent no particularly great problem. If, however, thegoods in question are fashion goods for which textiles in lengths ofonly a few 100 meters or less are required, the splicing of the yarns ofthe old and new warp beams and the presently therewith associated longdowntime of the machine are associated with such great costs that thewoven goods, produced on the basis of a small lot size, would be madeconsiderably more expensive.

There is, therefore, the initially described problem of creating thepossibility of making a splice which is especially able to withstandstresses, is easy to make and does not particularly disrupt thecontinuous operation of the machine during the production of textilegoods.

The above-described designs of a splice between two ends of yarn areexcellently suited for splicing the ends of the individual yarns of twogroups of yarns prior to being supplied to a processing machine, such asa weaving machine. According to the below-described further invention,the process for making a splice in the aforementioned context is suchthat the ends of yarn of the two groups of yarns are deposited,positioned to point at each other in the same direction, on a transversetape such that the ends of yarn of one group of yarns are opposite theends of yarn of the other group of yarns, the transverse tape extendingtransversely with respect to the groups of yarns across same in theregion of the ends of yarn to be joined, whereupon the ends of yarn arejoined to the transverse tape and therefore to each other throughactivation of a joining agent carried by the transverse tape, whereafterthe transverse tape is divided, by a cutter extending along the ends ofyarn and therebetween, into individual splices each with a longitudinalstrip, this resulting in each case in a continuous individual yarn withthe inclusion of the splice. This process permits the fast making of amultiplicity of substantially juxtaposed splices on the basis of twogroups of yarns. The process is easy to perform and therefore makes itpossible, also in the case of small lot sizes, to make the necessarysplices between the ends of yarn without this representing a factorwhich makes the end product particularly more expensive.

Making the splices by means of a transverse tape already provides asolid splice or join. However, it is also possible to improve thequality of the splice, namely by using two transverse tapes, wherein anopposing transverse tape is laid on the ends of yarn deposited on thefirst transverse tape, said opposing transverse tape likewise beingjoined to the ends of yarn through activation of a joining agent,whereupon the cutter divides both transverse tapes into two longitudinalstrips with a splice for each end of yarn.

With this process for splicing the ends of the individual yarns of twogroups of yarns, it is possible to proceed in a variety of manners.Thus, it is possible, as shown in FIG. 14, to dispose the splices 28within a group of yarns directly next to each other. Alternatively,however, it is possible for the splices of the ends of yarn 1 and 2 tobe disposed in staggered manner one behind the other, as presented inFIGS. 15 and 16 with respect to the splices 29 and 30. FIG. 15 shows tworows of splices within which the splices are disposed in staggeredmanner one behind the other; and FIG. 16 shows splices 30 which arearranged in four rows, the splices being disposed in staggered mannerone behind the other from end of yarn to end of yarn.

FIG. 17 shows a basic representation of a device with which the ends ofindividual yarns of two groups of yarns are joined together. This isbased on a process in which the ends of yarn 21 are deposited on atransverse tape 20, the ends of yarn 21 being covered by a furthertransverse tape, namely the opposing transverse tape 22, and bothtransverse tapes 20 and 22 being joined to the ends of yarn 21 throughactivation of a joining agent carried by the transverse tapes 20 and 22.The joining agent in this case is, for example, a cold-bonding agent.The transverse tapes 20 and 22 thus joined to the ends of yarn 21 arethen directed through pressing rollers 23 and 24, which bring about theintimate joining of the said three components 20, 21 and 22. At the sametime, the thus produced compound unit of the groups of yarns is furthertransported, the pressing rollers 23 and 24 drawing said compound unitfrom the supply rollers 25 and 26, onto which the two transverse tapes20 and 22 are wound.

After leaving the two pressing rollers 23 and 24, the groups of yarns,firmly held between the two transverse tapes 20 and 22, enter the regionof the cutter 27, which cuts through the individual transverse tapesalong the ends of the yarns, this resulting, for each end of yarn, intwo longitudinal strips as described hereinbefore, said longitudinalstrips then giving rise to a continuous individual yarn including thesplice which contains them. The device therefore provides continuousindividual yarns each with a splice of the above-described kind.

The placing of the ends of yarn in a position in which they can bebrought into relation for splicing is described in the aforementioned EP0 989 218 A1 (see therein, in particular, FIG. 6 to 7). The placing ofthe ends of yarn in a position in is which they can be spliced togetherin the sense of the above-presented invention is, therefore, of itselfknown.

1. A splice between two adjacent cut ends of yarn, wherein the cut endsof two lengths of yarn are positioned substantially coaxially andadjacent each other, and are each joined over a length of yarn to atleast one longitudinal strip, said longitudinal strip having on its sidefacing the external longitudinal surfaces of said two lengths of yarnjoining agent, said joining agent permanently binding those two lengthsof yarn to the longitudinal strip without integrally connecting theadjacent cut ends.
 2. Splice according to claim 1, characterized in thatthe joining agent is a bonding agent.
 3. Splice according to claim 1,characterized in that the joining agent is a thermoplastic.
 4. Spliceaccording to claim 3, characterized in that the longitudinal strip formsthe joining agent.
 5. Splice according to claim 1, characterized in thatthe longitudinal strip and the surface of the yarn comprise a joiningagent in the form of a hook-and-pile fastener.
 6. A splice according toclaim 1, wherein the adjacent cut ends of yarn are bevelled and thebevelled sections overlappingly point at each other.
 7. Splice accordingto claim 1, characterized in that the longitudinal strip (5, 6) iswrapped around the outer circumference of the yarn.
 8. Splice accordingto claim 1, wherein the longitudinal step comprises two opposinglongitudinal strips.
 9. Splice according to claim 8, characterized inthat the ends of the longitudinal strips project radially away from theyarn and are joined together.
 10. Splice according to claim 1, whereinthe adjacent cut ends of yarn are spaced apart.
 11. Splice according toclaim 10, characterized in that the longitudinal strips areoverlappingly joined together at the sides.
 12. Splice according toclaim 10, characterized in that the longitudinal strips are abuttinglyjoined together at the sides.
 13. Splice according to claim 10,characterized in that the longitudinal strips are joined together by atleast one further longitudinal strip.